Emily Dickinson Lexicon

RACK, n.³ [Sax. rec, steam; recan, to exhale; D. rook, rooken; G. rauch, rauchen; Sw. rök, röka; Dan, rog, roger. See Reek.]

Properly, vapor; hence, thin flying broken clouds, or portion of floating vapor in the sky. The winds in the upper region, which move the clouds above, which we call the rack. – Bacon. The great globe itself, / Yea, all which it inherit, shall dissolve, / And, like this unsubstantial pageant, faded, / Leave not a rack behind. – Shak. It is disputed, however, whether rack in this passage should not be wreck.